Mechanics of Composite Materials
EML4230 EML6232
ANNOTATED WEBPAGES ON COMPOSITE MATERIALS
Incredible Fish Armor Could Suit Soldiers
http://www.livescience.com/animals/080727-fish-armor.html
Last accessed September 3, 2008
This article is about the discovery of a composite material in nature. The focus is on the armor of an African fish called the Polypterus senegalus. MIT engineers took measurements of the fish's scale and its four layer material and also noted characteristics like shape, thickness, chemical properties and the orientation of the layers in an effort to better understand the armor and potentially utilize its features. Using the study of plants and animals to improve engineering knowledge is a very interesting concept and it shows how much people can still learn from the study of long existing natural systems. The article rather short and has few scientific details but it remains and interesting topic worth further exploration. Sean Rodby, Fall 2008
Testing composite materials can be challenging
http://www.instron.se/wa/applications/composites/challenges.aspx
Last accessed September 3, 2008
This webpage highlight some of the challenges encountered when testing and evaluating composite materials. They talk about particular challenges associated with measuring failure criteria such as fatigue and buckling as well. They also discuss challenges associated with preparing samples for the various tests aren't of consideration when dealing with metals and other homogenous materials. Michael Upham, Fall 2008
Information about vacuum infusion
http://www.fram.nl/workshop/controlled_vacuum_infusion/cvi.htm
Last accessed September 03, 2008
This is a page that summarizes the infusion process. Many of the advantages and disadvantages are explained thoroughly. The page revolves around a mans decision to use the vacuum infusion process, as apposed to hand lay up, to build a 44 ft f-39 sail boat. A handful of videos and pictures step you through the whole process from the cad design to the injection of the first main hull. David Lopez, Fall 2008
Breakthrough Thermoplastic Composite Sheet from GE & AZDEL Improves Safety & Performance for Passenger Train Components
http://www.jeccomposites.com/composites-news/405/Breakthrough-thermoplastic-composite.html
Last Accessed September 3, 2008
A new product called AZDEL* Rail-Lite* composite was recently introduced by GE and PPG Industries. This breakthrough material is a low-pressure, thermoformable, lightweight composite sheet that exhibits excellent flame, smoke, toxicity, and heat-release performance in large semi-structural panels for train interiors. This new product is made up of long glass fibers and epoxy, making the product very light but extremely durable. In fact almost half the material is air, making it half as heavy as current materials used in passenger trains. With the economy in the current fuel crisis that it is, using these panels would greatly reduce the fuel consumption of the train. This new composite offers excellent strength, stiffness, and a low coefficient of thermal expansion. It also provides good ductility, unlike traditional fiber-reinforced plastic materials or sheet-molding compounds. I found it interesting that this new material can be designed for zero shrinkage and does not require drying prior to thermoforming. The article was very interesting and we may be seeing much more of this material in the near future.
A "green" boat named Earthrace has set a new record for circumnavigating the globe.
http://www.npr.org/templates/story/story.php?storyId=92677191
Last accessed September 2, 2008
On July 18, 2008, Earthrace's Captain Pete Bethune went on National Public Radio's Talk of the Nation to discuss his bio-diesel, hemp-composite boat. Bethune recently circumnavigated the globe by sea in less than 61 days - 14 days faster than the previous record. Additional information about the boat including design specifications and its 50ft wave-piercing hull can be found at www.earthrace.net. Kevin Adcox, Fall 2008.
First Major GRP Road Bridge on the European Continent
http://www.netcomposites.com/news.asp?0
Last accessed September 2, 2008
A 27 meter, glass-reinforced plastic (GRP) bridge was recently constructed over the B3 Highway near Frankfurt, Germany. The bridge was pre-assembled near the highway and then lifted into position. Using two steel beams and a multi-cellular GRP deck, manufactured by Fiberline Composites, provided a corrosion resistant, lightweight, and easy to install alternative to concrete bridge designs. The innovative design is the result of research done by the Advanced Structural SystEms for Tomorrow's Infrastructure project of Europe. In my opinion, although span limitations exist on traffic-carrying bridges, it would be a good idea to incorporate this technology into bridge and walkway designs used in Florida, due to its resistance to corrosion and harsh conditions. Kevin Holmes, Fall 2008
What is carbon fiber?
http://www.wisegeek.com/what-is-carbon-fiber.htm
This is a short description of the carbon fiber and its applications. Matt Kunze, Fall 2008
Mosler Automotive
http://www.fabricdevelopment.com/frontpage.html
The website is the main page for the carbon composite distribution company Mosler Automotive for its carbon fiber supercars. Matt Kunze, Fall 2008
Argonne Researchers Create New Diamond-Nanotube Composite Material
http://www.anl.gov/Media_Center/News/2005/news050830.html
Last accessed September 4th 2008
August of 2005 researchers at Argonne National Research Laboratory successfully combined diamond, the world's hardest material, and carbon nanotubes, the world's strongest material, into a new advanced composite. The new composite can potentially be used for coatings, fuel cells, microelectronic industry, MEMS and NEMS, high definition displays and hydrogen storage. This is particularly remarkable because it marks the first time that a process has been established for making carbon nanotube composite structures. E Rice, Fall 2008
USCAR unveils new manufacturing process
http://composite.about.com/library/PR/1998/bluscar1.htm
This web page is about a new manufacturing process for large structural composites called programmable powder perform process (P4). It is a highly automated composite manufacturing process developed by researchers from United States Council for Automotive Research's (USCAR) Automotive Composites Consortium (ACC). The aim was to lower the cost and increase the manufacturing rate of composites made by the liquid molding process. Punya Basnayka, Fall 2008
Comparing a graphite/epoxy and glass/epoxy bow
http://www.engr.iupui.edu/me/courses/recurvebowfinalpres.ppt
Last accessed September 5, 2008
This webpage consists of a project submitted by students in Indiana University-Purdue University Indianapolis for composites course in fall-2000.
The project is comparing graphite epoxy and glass epoxy composite bow. The PowerPoint in the above link clearly demonstrates how the composite bow is modeled in ANSYS and how the loads are applied. The conclusion of the project is graphite epoxy is a better material to use for the composite bow because the stress distribution is uniform in it. The glass epoxy has stress concentrated on the outside curvature area and may fail over time in that area. Sri Harsha Garapati, Fall 2008
Impact of composites on aerospace
http://www.centennialofflight.gov
Last accessed September 5, 2008
This website article deals primarily with the particular impact that composite materials has had on the aerospace and aeronautical industry in the past 50 years. It explains how composites have literally been the gateway for more advanced planes, and technologies that would have been unachievable using metals. The main advantages of composites that are listed include lighter weight, higher strength to weight ratios, and the ability to customize the material to suit a particular application.
For instance, a point made by this article concerns the use of composites to build the experimental Grumman X-29 jet, which was one of the first planes to utilize a forward-swept wing design. Composites were utilized in the wing where it was necessary to allow bending in the downward direction, but not upwards as the craft flew. Traditional aluminum wings did bend upward as the jet reached higher speeds making this design inefficient. However, the use of composites allowed this design to be achieved when it might not have otherwise taken flight.
Although this article does sing the praises of composite materials, it does also hint at the inherent difficulties that go along with their use as well. Composites can be very difficult to repair, or even detect the need to repair. Often, more sophisticated methods are needed in order to detect a problem and this added sophistication means added expense. Also, if a composite component is damaged even slightly, it is often impossible to repair and must often be replaced. This is one of the chief advantages of aluminum and other metals over composites as they can often take much more punishment before failure, and can be repaired more easily.
Despite these disadvantages, the article emphasizes that composites will only be used more and more in the future, and some experts predict that as much as two-thirds of military craft will be composed of composites. This fact in itself stands as the testament to the useful nature of composite materials and their continued place in the future of engineering. Luke Snyder, Fall 2008
New Composite Material Is Almost Better Than Mother-of-Pearl
http://www.sciencedaily.com/releases/2008/03/080307102657.htm
Last accessed on September 1, 2008
Nacre, or mother-of-pearl, is a naturally occurring composite material that has a high degree of toughness and strength. Researchers at Zurich's Department of Materials have developed a new composite material that resembles nacre. Nacre only deforms about 1 to 2 percent before it breaks, but this new composite can deform up to 25% before breaking. One draw back of this new composite material is that researchers can't make it defect-free like natural nacre.
Cooperative Research Center for Advanced Composite Structures (CRC-ACS)
Last Accessed 1 September 2008
The CRC-ACS is a research group located throughout eastern Australia. The goal of the group is to is to "bridge research, development and implementation of composites technology" in support of the Australian composites industry. The website gives an overview of the center's main research areas: Aerospace, Maritime and General, as well as highlights new technologies such as Thermoset Composite Welding. Several success stories are presented where the group applied advanced composites research to solve high caliber industrial problems. S Chris Colbert, Fall 2008
How Self-Healing Spacecraft Will Work
http://science.howstuffworks.com/self-healing-spacecraft1.htm
Last accessed September 04, 2008
This webpage gives information about a newly developed composite material which is able to fix the microcracks formed inside it. The principle behind this smart material is detecting cracks as they grow and fixing them using a healing agent dispersed in the material. The article shows an illustrative figure in showing how this is exactly achieved. It identifies potential applications of the material including self-healing spacecrafts. Madhura Rajapakshe, Fall 2008.